Dynamo-electric machine



Feb. 17, 1931. R, B W|LL|AM5QN 1,792,720

DYNAIO ELECTRIC MACHINE Filed 06?'. 6, 1924 @Mon/www Patented Feb. 17, 1931 i UNITED i STATES lPATENT oFFlcE ROBERT B. TILLIAMSON, OF MILWAUKEE, WISCONSEN, ASSIGN'OR TO ALLIS-'CHAL- MERS MANUFACTURING COMPANY, OF MILWAUKEE, XVISCONSIN, A CORPORATION OF DELAWARE DYNAJSLIIO-ELEC'IIJRIGV MACHINE Application led October 6, 1924. Serial No. 741,899.

This invention relates to the ventilation of dynamo electric machines.

rl `he ventilation of dynamo electric machines is a diflicult problem, particularly in large machines. It is desirable to thoroughly ventilate not only the core in which the conductors are embedded but also the conductors themselves and also the rotor and its conductors. It is an object of the invention to provide means for accomplishing the foregoing results. l l

it is also an object to provide means whereby various elements of a dynamo electric machine may be supplied with Ventilating iluid which has not already passed over long paths and thus preheated. It is a further object to cool the various elements of a dynamo electric machine by Ventilating fluid that flows over comparatively short paths.

A more specific object is to provide means whereby the various elements oi a dynamo electric machine may be cooled by approximately independent streams of Ventilating fluid.

A further object is to provide means whereby a dynamo electric machine may be ventilated in a simple and eiiicient manner. Other objects will appear hereinafter as the description of theinvention proceeds.V

The novel Jfeatures of the invention will appear from this specification and the accompanying drawings forming a part thereof and showing one embodiment of said invention and all these novel features are intended to be pointed out in the claims.

In the drawings:

Fig. 1 is a fragmentary transverse section, taken in the general plane of a vent duct, of a dynamo electric machine embodying the invention.

Fig. 2 is a fragmentary sectional view along the line II-II of Fig. 1, looking inA the direction of the arrows. n p

Fig. 3 a fragmentary sectional view along the line IIIMIII of Fig. 1, looking in the direction of they arrow. y

Referring to thedrawings, the stator 1 of the dynamo electric machine hereshown cooperates with a rotor 2 spaced from the stator to form the usual air, gap. In the instance shown, the rotor would be the lield member and is usually provided with field conductors, not shown. The stator 1 is built up out of sector-shaped laminas 3 provided on the inner periphery thereoi:l with slots so that rows of conductors 4, 5 may be embedded therein. The slots form teeth 6. A given conductor 4 is here shown as separated radially from a. given conductor 5 in the same slot by means of a spacer 7 preferably of insulating material. The spacers 7 do not extend the full axial length ofthe conductors as may be seen from Fig. 3, but in the instance shown extend from the edge of one transverse radial vent duet 41, for example, to the edge of the next transverse radial vent .duct 42, thus leaving a peripheral passage between the respective radially superposed conductors at each vent duct. The conductors may be retained in the slots by any suitable form of wedges 8.

Each individual lamina 3 may be provided with any suitable means such as the dovetails 9 to position and fasten them to radial ribs 10, 11, 12, 18 providedy with `dove-tail slots, forming part of the stator yoke. The stator yoke is provided with a peripheral wall 14, here shown as provided with a plurality of outlets 15, 16. The walls 10, 11, 14 form a chamber over the stator core into which air or other Ventilating fluid may be admitted at, for example, an axial end of the dynamo electric machine. The walls 10, 11 thus also Y.torna an inlet 17 where air may enter vent ducts such as 41, 42, etc. (F ig. 3) The walls 1l, 12 and 10, 13 form outlet chambers through which air may leave from the outlet openings 18, 19, thus formed, and from the yoke outlets 15, 16 respectively. It is of llaminae are provided with spacers, many ol which also act as ballles, or guides as will be more fully set lforth.A A U-shaped baille 2O is provided radially below the wall 10 and so shaped and'disposed that air may enter the 1 U-shaped spaces thus formed from the inlet 17 through an opening 21 and leave said space at an opening 22 from where it passes through the outlet 19 and eventually from the machine through outletl. A radial baille 23 may be provided within the U-shaped kbaille 20 in order to cause air entering at opening 21toV4 travel radially inward to the arcuate end of the U-shaped baille before againv leaving by way of opening 22. Another substantially U-shaped path for air is provided by means of the radial ballles 2li, 25, disposed peripherally further away from the general plane of wall 10 and on opposite sides Vthereol, along with the arcuate battles 26, here shown as having their ends spacedjfrom each other and from the battles 24, 25. n As indicated by the arrows, some air is directed along kthis, U-shaped path from the inlet 17 to the outlet 19.'. Spaced radial ballles 28, 29, 30 are here shown as provided on a. line substantially half way between walls 10, 11. Another radial baille is disposed between baille 30 and ba-llle26. An arcuate baille 32 is provided between the radially outer locus of the row of conductors 4l and about radially below the U-shaped ballleshereinabovejdescribed. vided on the tooth portions ot the laminae between each pair of conductors 4. These spacers 33, preferably, do not extend radially inward further than theV radially innermost edge ol4 the row ol' conductors Ll, in order that the space between conductors 4 and 5 will be left open. One or more spacers 34 disposed between the several conductors 5 are also provided to brace the ends of the teeth. These spacers should preferably not extend further radially outward than the radially outermost edge of the row of conductors 5. A radial baille 35 is provided radially below baille 27 and peripherally to the lett thereof. Radial ballles 3S, 37, 38 here shown as spaced from each other are provided along the left hand edge of lamina 3. rllhese spacers also serve as bales.

The spacers and battles hereinabove de# scribed are repeated on lamina 3 between thev line ol baffles 28, 29, 30 and the right hand edge of said lamina. All the other lamin 3 are preferably provided with spacers and bafflessimilarly arranged.

Spacers 39, e() may be provided in order to better brace the dove-tails 9 Aand that One orinore spacersr 33 are pro' 17, some of it, as already mentioned, enters opening 21 and also the gap between baille 20 and baille 2li. This air follows a generally U-shaped path, as indicated by the arrows, from inlet 17 to outlet 19 and etliciently cools the major part of the core surface.

Another portion of the air admitted through inlet 17 passesfbetween bales 24e and 2S most ol" it going radially inward and between conductors 4e, 4d. A portion or this air passes between conductors le and 5e eventually lproceeding radiallyoutward, as indicated by the arrows. Another portion of the airv which passes radially inward between conductors le and ed continues onward and passes between vconductorsL 5e and 5d and when it reaches theair gap between the stator and rotor it turns to the lett asrindicated by the arrow. Eventually this airy passes radially outward between conductors 5e, 5f, and 5f, 5g, respectively, eventually reaching the outlet 19.V Some airY also passes" between conductors 4f and 5f as indicated by the arrow, Vlt will be noted thatthe baillel 32 serves to cause most ot the air coming radially inwards between ballles 26, 29 to go'between conductors le, 4d. A small part of it assumes a U-shapedpath radially below the bae 26. On the right hand side'ol baille 28 some ot the air passes radially inward, then divides and some of itpasses between condr-.ctors ed,

lo and between conductorseo, 4b. Some of CTX this air as indicated by the arrows, passes between conductor ec, 5c and conductors 470, 5b, respectively. Another portion continues radially inward eventually reaching the air gap and passing 'toward the right and then radially outward between Conductors 5a, 5?) from where it proceeds and finally reaches the outlet 18. The U-shaped paths on the right hand side of lamina 3 are substantiaL 'iz lydthe Vsame as already described for the lett si e.

The radial baffles 32 are preferably ex tended radially inwards so as to leave no air gap between, for example, conductor L1e andthe battle. rllhis prevents air from being blown 'across the path of the air moving between conductors 41e and 4f, 'for example.

It will be noted that approximately Vhall oli' the air admitted through inlet 17 eventually reaches the outlet 19 and the other approximate half eventually reaches the outlet 18.

It should be understood that it is not def It is claimed and desiredto secure by Letters Patent:

l. In combination with a core for a dynamo electric machine having a radial Ventilating passage, conductors radially spaced from each other and embedded in the inner periphery of said core, and means for directing air through said passage radially inward, circumferentially through the space between said conductors and in planes transverse to the longitudinal axis of said core, and radially outward.

2. In combination with a core for a dynamo electric machine having a radial Ventilating passage, conductors peripherally spaced from each other and embedded in the inner periphery of said core, a second core disposed within and spaced from the inner periphery of said first core to form an air gap,'and means for directing air through said passage between certain of said conductors radially inward, then circumferentially through said air gap and in planes transverse to the longitudinal axis of said core, and then radially outward between others of said conductors.

3. In combination with a core for a dynamo electric machine having a radial Ventilating passage, conductors peripherally and radially spaced from each other and embedded in the inner periphery of said core, a second core disposed within and spaced from the inner periphery of said first core to form an air gap, and means for directing air through said passage between certain of said conductors radially inward, a portion of said air circumferentially between radially spaced conductors and in planes transverse to the longitudinal axis of said core, and another portion circumferentially .through said air gap and in planes transverse to the longitudinal axis of said core.

4. In combination with a core for a dynamo electric machine having a radial Ventilating passage, a second core disposed within and spaced from the inner periphery of said first core to form an air gap, and means for directing a flow of air under pressure through said passage radially inward to said air gap, and means for producing zones of lower pressure on opposite peripheral sides of said flow whereby said flow is caused to divide and flow in opposite circumferential direct-ions in said air gap and in planes transverse to the longitudinal axis of said core.

5. In combination with a core for a dynamo electric machine having a radial Ventilating passage, a second core disposed Within and spaced from said first core to form an air gap, conductors embedded in the inner periphery of said first core, means for directing a flow of' air under pressure through said passage radially inward toward said air gap, and means for producing zones of lower pressure on opposite peripheral sides in planes transverse to the longitudinale-.Xie

of said core 4and that porti-on which reaches .the air gap is caused to flow iii-opposite .cir-

cumferential directions in said air ga-pfand in planes transverse tothe longitudinal axis oysaid bore. Y

6. VIn combination, a core for -a dynamo'- electric machine, :a secondcoredisposed with- `and spaced from said first core yto form an air gap, conductors embeddedin the inner lperiphery of said rst core, said first core having aradial Ventilating passage extending from the outer to the inner periphery of said core and communicating with saidair gap, means wheieby a plurality of peripheral inlets for said passage are formed ,alternating with a plurality of outlets therefor, and radial bafi'le means disposed peripherally approximately half Way between the edges of each outlet and extending substantially to the outer peripheral locus of said conductors.

7. In combination, a core for a dynamoelectric machine, a second core disposed within and spaced from said first core to form an air gap, conductors embedded in the inner periphery of said first core, said first core having a radial Ventilating passage extending from the outer to the inner periphery of said core and communicating with said air gap, means whereby a plurality of peripheral inlets for said passage are formed alternating with a plurality ofv outlets therefor, and baffle means of general U-shape extending from a given inlet to an adjacent outlet, and similar baffle means extending from the same inlet to the other adjacent outlet, said U-shaped bafiie means extending radially inward to leave a restricted passage between them respectively and the outer peripheral locus of said conductors.

8. In combination with a core for a dynamo-electric machine having a radial ventilating passage in a single plane, means whereby a plurality of peripheral inlets for said passage are formed alternating with a plurality of outlets therefor, conductors embedded in the inner periphery of' said core, baie means of general U-shape extending from a given inlet to an adjacent outlet, and similar baiile Imeans extending from the same inlet to the other adjacent outlet, said U-shaped bafiie means extending approximately to the locus of the radially outer periphery of said conductors, and baille means having a radial component disposed between said locus and the inner end of said U-shaped baffle means.

9. In combination, a core for a dynamoelectric machine, a second core disposed within and spaced from said first core to form an air gap, conductors embedded in the inner periphery of said first core, said irsty core having a radial Ventilating passage extending from the outer to the inner periphery of said EGO iii)

core Vand communicating with said air gap, 'f means whereby a plurality of peripheral V` inlets forvsaid passage are 'formed alternating :with `a plurality of outletsv therefor, baille means of. general U-shape 'extending from a given inlet to an adjacent outlet, and similar baffle means extending from the same inlet to the other adjacent outlet, saidU-'shaped baille means extending radiallyinward to leave a restricted-passage between them respectively andthe outer peripheral locus of said conductors, and a radial baflle'disposed peripherally approximately half-way between the edges of each Outlet Yand extendingk substantially .to the outer peripherallocus of said conductors. v

In testimony whereof, the signature of the inventor is aflixed hereto. t n Y ROBERT B. WILLIAMSON: 

